Nick Bosa comes from an accomplished football family. From left: Nick's dad John, who played for the Miami Dolphins; brother Joey, who plays for the Chargers; Nick; his uncle, Eric Kumerow, who played for the Dolphins; and Jake Kumerow, a wide receiver for the Packers.

Photo: Courtesy Cheryl Bosa /

Long before he entered the family business of chasing quarterbacks, before he helped rejuvenate the 49ers and became a Defensive Rookie of the Year contender, Nick Bosa was simply a 7-year-old who didn’t get his way.

He wanted to play football. His parents wanted him to wait. And that’s how young Nick ended up sprawled on the kitchen floor of the family’s home in Miami, arms and legs flailing, screaming, “If you don’t let me play, I’m going to die!”

Cheryl Bosa and her then-husband, John, had good reason to prefer their sons, Joey and Nick, delay their introduction to the sport. John Bosa, a first-round draft choice of the Dolphins in 1987, blew out his knees and lasted only three years in the NFL.

He knew firsthand the game’s physical risks, so he tried to keep his boys away from contact as long as possible.

“Their mom and I lost that fight,” John said. “It was a miserable failure.”

Before long, Cheryl Bosa found herself making a daily, 45-minute drive every fall to Pembroke Pines. That was the best junior football program in the area, so Cheryl picked up her kids from school, fed them in the car and made sure they did homework on picnic tables before practice.

Joey Bosa (left) flexed his big-brother muscles when he and Nick were younger, but they became close after spending one season as teammates at St. Thomas Aquinas High School in Fort Lauderdale, Fla.

Photo: Courtesy Cheryl Bosa

Joey and Nick loved the game, even if their dad’s career ended several years before they were born. John Bosa didn’t push them, didn’t coach them and didn’t talk much about his playing days. He wanted to watch, just another dad in the stands.

Still, much as John craved the adrenaline of sacks, so did his sons. Cheryl Bosa vividly remembers sitting in a folding chair between fields and seeing little Nick walk up to his coach, tug on his shirt and say something. The coach shrugged and pointed to a group of kids, and Nick happily scampered away.

Later, when his mom asked about the conversation, Nick explained the coach had put him on offense. He desperately wanted to play defense, even then.

“I just wanted to be tackling the guy with the ball, not be the guy with it,” Nick Bosa said.

Now, at 22, Bosa offers a study in contrasts. He’s full of bravado on the field, quick and aggressive and relentless; his eight sacks and frequent pressure on opposing quarterbacks are a big reason the 49ers have the league’s top-ranked defense.

He plays defensive end, as John did and as Joey, 24, currently does for the Los Angeles Chargers. Cheryl’s brother, Eric Kumerow, also played the position for three years with the Dolphins, as John Bosa’s teammate. They are the First Family of Pass Rushers. (Nick and Joey’s cousin, Jake Kumerow, is a wide receiver for Green Bay.)

Nick Bosa grew up with no choice but to tussle with his brother, who is 27 months older. Their backyard recreation invariably became competitive and physical, from the trampoline to the basketball hoop in the swimming pool. Games often ended with Nick returning to the house in tears.

And on the rare occasions when Nick won, well, Joey was not the most gracious loser.

The 49ers’ Nick Bosa greets General Manager John Lynch after the 20-7 win over the Rams in Los Angeles on Oct. 13.

Photo: Scott Strazzante / The Chronicle

“I was a total a—hole,” Joey said in a phone interview. “I would just beat him up if I lost. It probably toughened him up, for sure.”

As time passed, sibling tension subsided. Joey and Nick were three grades apart, so they spent only one season as teammates. That was in 2012 at powerhouse St. Thomas Aquinas High in Fort Lauderdale, Fla., (the family had moved there from Miami) when Joey was a senior and Nick was a 215-pound freshman, holding his own as the varsity nose tackle.

That season, complete with a special brotherly handshake, brought the Bosas closer. Joey soon left to play at Ohio State. Nick visited him there and learned the same advanced techniques, including martial-arts training, from defensive line coach Larry Johnson.

Then, when Joey bolted for the pros in 2016, Nick essentially replaced him at Ohio State (his mom and uncle’s alma mater). By then, he had modeled his game after his brother’s, including the same perfectionist tendencies that led to those perpetual conflicts when they were younger.

“That’s one of the wonderful things Joey taught his little brother — how to never be happy with certain levels of success,” John Bosa said. “Always work at your craft, always get better.”

The similarities between Nick and Joey stretch beyond their playing style. They share the same pigeon-toed gait as their dad, the same “mope-around walk,” as Joey put it, with their shoulders kind of rolling forward.

“It’s hard to explain, but everything we do looks the same,” Nick said. “The moves we use, the way we run, the way we walk, the way we stand. Everything just looks similar.”

The 49ers’ Nick Bosa pressures the Steelers’ Mason Rudolph in the second quarter at Levi’s Stadium in Santa Clara in September.

Photo: Scott Strazzante / The Chronicle

Or, as longtime St. Thomas Aquinas coach and athletic director George Smith said, “They’re the same guys, basically. Very nice and polite. Then, when the lights come on, two lunatic football players.”

Nick Bosa differs from his brother in one notable way: He’s more politically conscious, which brought unwelcome attention ahead of the NFL draft in April. He had wandered into delicate territory on Twitter in college, posting his support for President Trump and his distaste for former 49ers quarterback Colin Kaepernick. Bosa, at 16, also “liked” two Instagram posts (from a high school friend) that included homophobic and racist hashtags.

He apologized at his introductory news conference in April and has not publicly addressed the controversy since then. His social media posts these days are mostly bland and football-focused, such as one recent meme making fun of Michigan head coach Jim Harbaugh after Ohio State routed the Wolverines.

The tweet calling Kaepernick “a clown” came after he wore a T-shirt (to a postgame session with reporters in August 2016) showing Fidel Castro talking to Malcolm X. John Bosa said Nick grew up with several Cuban American friends in South Florida, and they shared stories about the terrible conditions their families endured in Cuba under Castro.

“That tweet had nothing to do with Kaepernick taking a knee, or police brutality,” John Bosa said. “It had to do with him wearing a Fidel Castro T-shirt.”

As for the earlier Instagram “likes,” Cheryl Bosa suggested they were impulsive and came from an “idiot teenager.” She said of Nick, “I know my kid’s character. He’s the kindest, gentlest person ever.”

Three 49ers players insisted Bosa’s previous social media activity wasn’t an issue in the locker room, where he routinely mingles with teammates of diverse backgrounds — much as he did on the youth team in Pembroke Pines, which was predominantly African American.

Bosa’s work might be rooted in the redundant grind of training, practice and video study, but the reward comes in the exhilaration of making a big play.

That’s partly why he, like his dad and brother before him, chose to play defense. Bosa covets the one-on-one element of line play, the chance to beat his man to make a game-changing tackle.

Or, better yet, sack the quarterback.

Nick Bosa (left) and brother Joey, currently with the Chargers, follow in father John’s footsteps.

Photo: Courtesy John Bosa

“It’s like a touchdown, home run or 3-pointer,” he said. “I like the fact that on third down, everybody runs off the field. It’s a stop. You ended the drive.”

John Bosa had only seven sacks in his injury-shortened NFL career, but he savored each one. (Nick matched his dad halfway through his rookie season.) John recalled with great clarity one sack at Boston College (against Pitt), and another with the Dolphins against Philadelphia’s Randall Cunningham on “Monday Night Football.”

“The first time you flatten the quarterback and knock the ball loose … if that doesn’t get your blood flowing, then something is wrong with you,” John said. “It’s the coolest feeling.”

Other football families have made their mark on the game, including the Mannings at quarterback, the Matthews clan (mostly) at linebacker and the Watt brothers at various positions. Now the Bosas are building an impressive lineage at defensive end.

San Francisco 49ers

John Bosa was the 16th overall pick in ’87, Joey was No. 3 overall in 2016 and Nick was No. 2 overall this year. Cheryl’s side of the family also brings some history: Not only did her brother and nephew reach the NFL, her biological father, Palmer Pyle (who didn’t raise her), played guard for three teams in the 1960s.

Nick and Joey Bosa frequently talk about techniques and the tendencies of certain opponents. They seldom consult John on these details, because the game was so much different when he played 30-plus years ago.

Still, he imbued his sons with a necessary ingredient for life in the trenches, tongue only partly in cheek.

Nick: “I think my dad gave me the passion, the work ethic, the hatred for offensive linemen.”

Joey: “Our dad’s mind-set was, ‘There’s no chance in hell you can block me.’ … I have friends who are O-linemen. Well, I wouldn’t call them friends. They’re annoying.”

John: “Even though they were my teammates, I couldn’t be friends with O-linemen. I don’t like them. They’re fat and ugly.”

Joe Staley is hard to hate, but he is an offensive tackle. And on the first day of training camp in July, he quickly learned how the Bosas’ disdain for their opponents translates on the field.

Nick Bosa hit Staley with an uncommon blend of quickness and savvy belying his age (21 at the time). Staley was suitably impressed.

“He’s probably the most complete rookie I’ve ever seen come out of college,” Staley said.

San Francisco 49ers defensive end Nick Bosa (97) and linebacker Fred Warner celebrate Bosa's sack of Carolina Panthers quarterback Kyle Allen during the first quarter of an NFL football game, on Sunday, Oct. 27, 2019 in Santa Clara, Calif.

Photo: D. Ross Cameron / Special to The Chronicle

There are many examples in Bosa’s maiden season. He propelled himself past Cleveland’s Greg Robinson on Oct. 7, leading to a sack and forced fumble; he eluded Washington’s Donald Penn for a game-ending sack Oct. 20; and he dominated Carolina with three sacks and an interception Oct. 27.

Pro Football Focus ranks Bosa as the league’s No. 1 rookie through the season’s first 13 weeks, by a wide margin.

As his production and reputation grow, opponents are double teaming him more often. Arizona wide receiver Larry Fitzgerald emphatically knocked Bosa to the ground on one play Nov. 17, mostly because he was focused on the tackle across the line.

Fitzgerald later approached Bosa and said, “Sorry, man, gotta slow you down somehow.”

This doesn’t surprise 49ers head coach Kyle Shanahan. He joked about watching video of Bosa in college and wondering if his dad ran him through pass-rush drills at age 3. The twist on this, of course: John Bosa didn’t coach his sons when they were growing up.

They took his enthusiasm for the game, worked hard and ultimately joined the family business.

“It’s a genetic phenomenon,” Cheryl Bosa said. “To have two kids playing at this level, that’s crazy.”

Ron Kroichick has worked at the San Francisco Chronicle since 1995, when he came from the Sacramento Bee. In spring 2020, during the coronavirus pandemic, he has temporarily moved to Metro to cover higher education and general-assignment news. In normal times, Kroichick is The Chronicle’s golf columnist, covering the AT&T Pebble Beach Pro-Am and all major championships in Northern California (including the 2019 U.S. Open at Pebble Beach and 2020 PGA Championship at Harding Park). He also writes features on the Warriors during the NBA season, and on various other topics – ranging from the 49ers/NFL and major-league baseball to college football and basketball – the rest of the year.